A strain of Escherichia coli bacteria — that lurks in retail chicken and turkey products — can be passed on to people, causing urinary tract infections and other serious conditions, a study has found. Many people think of urinary tract infections (UTIs) as a common and minor annoyance, but invasive UTIs that involve the kidneys or blood can be life-threatening. More than 80 per cent of UTIs are caused by E coli, but only a few strains are responsible for most of the serious infections. One type of E coli, called E coli ST131, is particularly adept at travelling from the bladder to the blood and kills thousands of people each year.
It is unknown how most people pick up E coli ST131 infections. Previous studies suggested that retail meat was not a source, but new research suggests that these earlier studies may have been too narrowly focused. Scientists including those from the George Washington University in the US, showed that there are multiple strains of E coli ST131 and that one strain in particular may be passed to people via contaminated poultry meat. They conducted a one-year longitudinal study where they analysed retail chicken, turkey and pork purchased from major grocery chains in the US.
During the same year, the team also collected and analysed urine and blood isolates from hospitalised patients in the area. The team found E coli in nearly 80 per cent of the 2,452 meat samples and in 72 per cent of the positive urine and blood cultures from patients.
E coli ST131 was the most common type infecting people and was also present on the meat samples. Next, the team had to find out just how closely related these bacteria were to one another, or, importantly whether people had acquired them from poultry.
To find out, researchers studied the genomes of the E coli cells. They discovered that that almost all of the E coli ST131 on the poultry products belonged to a particular strain called ST131-H22 and carried genes that helps E coli thrive in birds. This same poultry-adapted strain was also found to be causing UTIs in people. “In the past, we could say that E coli from people and poultry were related to one another, but with this study, we can more confidently say that the E. coli went from poultry to people and not vice versa,” said Price. Currently, poultry products are not routinely tested for the kind of E coli strains that can cause UTIs. These findings underscore the importance of cooking poultry thoroughly and handling it carefully in the kitchen, Price said.